[Sync] Refactor sync datatype error handling.

chrome/browser/prefs/pref_model_associator.cc

 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/prefs/pref_model_associator.h"
 
 #include "base/auto_reset.h"
 #include "base/json/json_reader.h"
 #include "base/logging.h"
 #include "base/tracked.h"
@@ skipping 98 matching lines @@
     // we'll send the new user controlled value to the syncer.
     return;
   }
 
   // Make sure we add it to our list of synced preferences so we know what
   // the server is aware of.
   synced_preferences_.insert(pref_name);
   return;
 }
 
-bool PrefModelAssociator::MergeDataAndStartSyncing(
+SyncError PrefModelAssociator::MergeDataAndStartSyncing(
     syncable::ModelType type,
     const SyncDataList& initial_sync_data,
     SyncChangeProcessor* sync_processor) {
   DCHECK_EQ(type, PREFERENCES);
   DCHECK(CalledOnValidThread());
   DCHECK(!sync_processor_);
   sync_processor_ = sync_processor;
 
   SyncChangeList new_changes;
   std::set<std::string> remaining_preferences = registered_preferences_;
@@ skipping 21 matching lines @@
 
   // Go through and build sync data for any remaining preferences.
   for (std::set<std::string>::iterator pref_name_iter =
           remaining_preferences.begin();
        pref_name_iter != remaining_preferences.end();
        ++pref_name_iter) {
     InitPrefAndAssociate(SyncData(), *pref_name_iter, &new_changes);
   }
 
   // Push updates to sync.
-  sync_processor_->ProcessSyncChanges(FROM_HERE, new_changes);
+  SyncError error =
+      sync_processor_->ProcessSyncChanges(FROM_HERE, new_changes);
+  if (error.IsSet()) {
+    return error;
+  }
+
   models_associated_ = true;
-  return true;
+  return SyncError();
 }
 
 void PrefModelAssociator::StopSyncing(syncable::ModelType type) {
   DCHECK_EQ(type, PREFERENCES);
   models_associated_ = false;
   sync_processor_ = NULL;
 }
 
 Value* PrefModelAssociator::MergePreference(
     const PrefService::Preference& local_pref,
@@ skipping 125 matching lines @@
       continue;  // This is not data we care about.
     // TODO(zea): plumb a way to read the user controlled value.
     SyncData sync_data;
     if (!CreatePrefSyncData(name, *pref->GetValue(), &sync_data))
       continue;
     current_data.push_back(sync_data);
   }
   return current_data;
 }
 
-void PrefModelAssociator::ProcessSyncChanges(
+SyncError PrefModelAssociator::ProcessSyncChanges(
     const tracked_objects::Location& from_here,
     const SyncChangeList& change_list) {
-  if (!models_associated_)
-    return;
+  if (!models_associated_) {
+    SyncError error(FROM_HERE,
+                    "Models not yet associated.",
+                    PREFERENCES);
+    return error;
+  }
   AutoReset<bool> processing_changes(&processing_syncer_changes_, true);
   SyncChangeList::const_iterator iter;
   for (iter = change_list.begin(); iter != change_list.end(); ++iter) {
     DCHECK_EQ(PREFERENCES, iter->sync_data().GetDataType());
 
     std::string name;
     sync_pb::PreferenceSpecifics pref_specifics =
         iter->sync_data().GetSpecifics().GetExtension(sync_pb::preference);
     scoped_ptr<Value> value(ReadPreferenceSpecifics(pref_specifics,
                                                     &name));
@@ skipping 28 matching lines @@
     // policy controlled.
     pref_service_->Set(pref_name, *value);
 
     // Keep track of any newly synced preferences.
     if (iter->change_type() == SyncChange::ACTION_ADD) {
       synced_preferences_.insert(name);
     }
 
     SendUpdateNotificationsIfNecessary(name);
   }
+  return SyncError();
 }
 
 Value* PrefModelAssociator::ReadPreferenceSpecifics(
     const sync_pb::PreferenceSpecifics& preference,
     std::string* name) {
   base::JSONReader reader;
   scoped_ptr<Value> value(reader.JsonToValue(preference.value(), false, false));
   if (!value.get()) {
     std::string err = "Failed to deserialize preference value: " +
         reader.GetErrorMessage();
@@ skipping 53 matching lines @@
     InitPrefAndAssociate(SyncData(), name, &changes);
   } else {
     // We are already syncing this preference, just update it's sync node.
     SyncData sync_data;
     if (!CreatePrefSyncData(name, *preference->GetValue(), &sync_data)) {
       LOG(ERROR) << "Failed to update preference.";
       return;
     }
     changes.push_back(SyncChange(SyncChange::ACTION_UPDATE, sync_data));
   }
-  sync_processor_->ProcessSyncChanges(FROM_HERE, changes);
+
+  SyncError error =
+      sync_processor_->ProcessSyncChanges(FROM_HERE, changes);
+  if (error.IsSet())
+    StopSyncing(PREFERENCES);
 }